This background section is provided for the purpose of generally describing the context of the disclosure. Work of the presently named inventor(s), to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The Serial ATA (SATA) interface defines power states that a SATA device or host (both occasionally referred to herein as “SATA devices”) can enter to reduce power consumption. Out-of-band (OOB) signals received by a squelch detector are used to communicate during these low-power states. In the lowest-power states, power consumption is limited by the power used by the squelch detector. The SATA specification defines minimum and maximum amplitudes at which to reject and detect the OOB signals, as well as minimum and maximum durations for elements of the OOB signals used to determine OOB signaling sequences such as COMINIT, COMRESET, and COMWAKE. The squelch detector must consume power to correctly measure these amplitudes and durations, significantly increasing the power consumption of SATA devices in low-power states.